Existing antenna units and RRUs provide a performance improvement in terms of signal integrity and energy consumption when they are in close proximity with each other or coupled together in a single integrated product. To make the integrated solution less obtrusive it is desirable to install the units as close to the mast or wall on which they are mounted as possible which then presents a challenge for cabling and cooling of the unit. Traditionally rectangular shapes have been used for the elongated housing of the RRU and antenna unit. A more recent development are RRUs and antenna units with a cylindrical housing, which is less visually impactive on the environment, provides a good shape to reduce wind load, can be mounted close to 25 millimeters (mm) on a support structure such as a pole which also reduces the forces on the mounting bracket due to a small turning moment. The cylindrical shape of the housing of the unit and its close distance to the pole or wall has mechanical advantages but also presents a challenge in terms of cabling and access to external interfaces.
Presently, there are two approaches to cabling a RRU or antenna unit. The first is to use only external connectors but this means bigger connectors with integrated ingress protection seals which are both expensive and on products with a small footprint they are difficult/impossible to integrate into the design. The second approach is to have a maintenance cavity in the housing which allows for the use of cheaper internal connectors but requires a cover or door which is easy to access and provides a reliable ingress protection seal around the edges and cables. A current solution uses a maintenance cavity with a door that is hinged towards the rear of the unit and opens downwards. In this current solution the cables are installed from the rear (the side of the support structure) of the unit which means the maintenance cover (door) gets in way and the cables must be threaded through from the rear. The minimum distance to the support structure is defined by the cables which exit the maintenance cavity at an angle towards the support structure. Cable bending radiuses are too tight for the current cables. The mounting bracket and maintenance cover block the airflow in the lower part of the heatsink.